A method for implementing the strong field reselection mechanism based on DRTD locomotive station

Abstract

The present invention discloses a method for implementing a DRTD locomotive station strength reselection mechanism. The method is implemented based on a railway DRTD communication system, wherein the communication system includes a train CIR device and a ground fixed radio station. During operation in the DRTD mode, the train CIR device collects the real-time changes in the field strength of the fixed radio station of the station and the fixed radio station of the neighboring station, determines the fixed radio station with the best field strength, and automatically completes the registration service. The present invention implements the function of the train CIR device automatically selecting the fixed radio station with the best field strength for registration, reduces the problem of communication loss and voice quality degradation caused by signal deterioration due to being away from the original registered fixed radio station, and realizes the intelligent and automated operation of the train.

Description

Technical Field

[0001] The invention relates to a method for automatically identifying field strength of a railway train in a DRTD mode, and in particular to a method for realizing a DRTD locomotive station strength field reselection mechanism. Background Art

[0002] In recent years, the development and application of a train control system that supports the 400MHz digital frequency band can effectively improve the utilization rate of wireless frequency resources, enhance the reliability of system communications, meet the needs of railway users, comply with the technical development direction and policy orientation of the country and the industry, effectively ensure railway driving safety, and promote the application and promotion of digital intercom technology in railway communications. However, in the process of train operation, it is inevitable to encounter the problem of changing field strength trends from one ground fixed station to another ground fixed station, or the problem of a sudden drop in temporary field strength signals due to obstacles. Therefore, it is urgent to develop a method that can automatically determine the field strength between fixed stations to reduce the problem of weakening field strength, avoiding the problem of poor train communication quality due to obstacles or mislocking to weaker ground fixed stations, so as to realize the intelligent and automated strong field reselection mechanism. Summary of the invention

[0003] In order to reduce the problem of the field strength weakening but not yet lower than the threshold value (lower than -107dBm), or the problem of the train communication quality deteriorating or mistakenly locking to a weaker ground fixed station due to the obstruction of obstacles, the present invention provides a method for implementing the strong field reselection mechanism based on the DRTD locomotive station. During the operation of the train CIR equipment in the DRTD mode, by collecting the real-time changes in the field strength of the fixed station of the station and the fixed station of the neighboring station, the fixed station with the optimal field strength is determined and the registration service is automatically completed. This method can realize the real-time judgment of the optimal field strength of the ground fixed platform, prevent the situation where the signal drops sharply and then recovers due to the obstruction of obstacles, and ensure the call quality between the locomotive station and the ground fixed platform in the DRTD mode in real time.

[0004] The technical solution adopted by the present invention is: a method for implementing a strong field reselection mechanism based on a DRTD locomotive station, wherein the strong field reselection mechanism is implemented based on a railway DRTD communication system, the communication system includes a train CIR device and a ground fixed radio station, and the implementation method of the strong field reselection mechanism is: determining a train CIR device startup scanning mechanism and a judgment principle for a train CIR device strong field reselection mechanism.

[0005] 1. Train CIR equipment startup scanning mechanism

[0006] When the train CIR device of the DRTD locomotive station is turned on or switched to DRTD mode, the power-on scanning mechanism is first performed to scan all frequency points in the frequency group in turn, read the field strength value once for each frequency point, and after polling each frequency point, lock on the frequency point with a high field strength value. The train CIR device performs position update registration with the ground fixed station, and the ground fixed station after the update registration is defined as this station.

[0007] 2. Judgment Principles of the Strong Field Reselection Mechanism of Train CIR Equipment

[0008] a. After the train CIR device successfully updates the location registration with the station, it collects multiple field strength values ​​of the station during the journey, calculates the average value of the multiple field strength values, and uses the average value of the multiple field strength values ​​as the field strength value of the station; if it is found that the field strength value of the station decreases during the collection process, the train CIR device enters the frequency point preparation reselection state.

[0009] b. Determine whether the field strength value of this station is lower than the preset field strength value. If so, initiate fast switching and immediately switch to the frequency points of the train CIR equipment of two adjacent ground fixed stations in turn to collect field strength values, and select the ground fixed station with the higher field strength value for position update registration.

[0010] c. Determine whether the field strength values ​​of two adjacent ground fixed stations are higher than the field strength value of this station. If so, register for location update with the adjacent fixed station with a higher field strength value; if not, return to step a.

[0011] d. Repeat steps a, b, and c to ensure the implementation of the judgment principle that the train CIR equipment and the ground fixed station with the highest field strength value perform real-time position update registration to realize the strong field reselection mechanism in the DRTD communication system.

[0012] The judgment principle of the strong field reselection mechanism of the train CIR equipment is: regardless of whether the train CIR equipment is in the frequency preparation reselection state, as long as there is an adjacent station frequency higher than the current station frequency in the first scan, the second adjacent station frequency is scanned immediately, and the frequency with the highest field strength value is selected. The field strength value of the highest frequency is scanned three times, and the time interval between each scan is 3 seconds; if two of the three scan results are higher than the field strength value of the current station frequency, the position update registration is started to the adjacent station ground fixed radio; if two of the three scan results are lower than the field strength value of the current station frequency, the frequency preparation reselection state is immediately restored.

[0013] The beneficial effects of the present invention are as follows: the present invention realizes the strong field reselection mechanism of the DRTD locomotive station, so that the CIR locomotive station avoids the problem of mislocking to a weaker ground fixed station due to the weakening of the field strength but not yet below the threshold value (below -107dBm) or the deterioration of the train communication quality due to the obstruction of obstacles during continuous driving, and realizes the real-time judgment of the optimal ground fixed platform field strength, prevents the situation where the signal drops sharply and then recovers due to the obstruction of obstacles, and guarantees the call quality of the locomotive station and the ground fixed platform in the DRTD mode in real time, realizing the intelligence and automation of the strong field reselection mechanism. This method takes into account the real-time and mutation factors of the locomotive operation, and is implemented by means of rapid scanning and cumulative average value, which is more efficient and accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a block diagram of the connection principle of the railway DRTD communication system of the present invention;

[0015] Figure 2 is a flow chart of the power-on scanning mechanism in an embodiment of the present invention;

[0016] Figure 3 It is a flow chart of the determination principle of the strong field reselection mechanism of the train CIR equipment in the embodiment of the present invention. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0018] Reference Figure 1 The strong field reselection mechanism is based on the railway DRTD communication system, which includes train CIR equipment and ground fixed radio stations. Figure 1 As shown, the train CIR equipment receives the field strength frequency points fH1, fH2, and fH3 of fixed radio stations A, B, and C in real time for comparison and judgment, and registers and updates with the ground fixed radio station with the strongest field strength value.

[0019] The implementation method of the strong field reselection mechanism is: determine the train CIR equipment power-on scanning mechanism and the judgment principle of the train CIR equipment strong field reselection mechanism.

[0020] Reference Figure 2 After the CIR locomotive is powered on or switched to DRTD mode, the power-on scanning mechanism process is performed first. The power-on scanning mechanism process performs the following operations:

[0021] 1-1. The train CIR equipment scans the three frequencies fH1, fH2 and fH3 in the frequency group in turn, reads the field strength value once at each frequency point and records the field strength value separately.

[0022] 1-2. After the train CIR equipment polls the three frequency points fH1, fH2, and fH3, it compares the field strength values ​​of the three frequency points and locks on the frequency point fH2 with the higher field strength value.

[0023] 1-3. The train CIR equipment performs position update registration with the ground fixed station B at the fH2 frequency with a high field strength value; the ground fixed station B after the update registration is defined as this station.

[0024] Reference Figure 3 , the determination principle of the strong field reselection mechanism of train CIR equipment

[0025] When the train CIR equipment successfully updates its position to the station (ground fixed platform B with the strongest field strength value), the judgment principle of the train CIR equipment field strength reselection mechanism is implemented during the operation along the way. The judgment principle is:

[0026] 2-1. During the operation of the train CIR equipment, the field strength value of the current fH2 frequency point of the station is scanned once every 1 second. After collecting the field strength values ​​of 5 fH2 frequencies, the average value of the 5 field strength values ​​is calculated, and the average value of the field strength values ​​of the 5 fH2 frequencies is used as the field strength value of the ground fixed radio station B of the station; if it is found that the field strength value of the fH2 frequency point of the ground fixed radio station B of the station decreases during the collection process, the train CIR equipment enters the frequency point preparation reselection state.

[0027] 2-2. The train CIR equipment scans and records the field strength values ​​of the neighboring fH1 and fH3 frequencies alternately once every 15 seconds. When the field strength value of the fH2 frequency point of the train CIR equipment decreases for three consecutive times, the train CIR equipment enters the frequency point preparation reselection state, and the train CIR equipment begins to shorten the scanning time to once every 5 seconds for recording the field strength values ​​of the neighboring fH1 and fH3 frequencies.

[0028] 2-3. Determine whether the field strength value of the frequency point fH2 of the local station is lower than the preset threshold value (lower than -107dBm). If so, initiate fast switching and immediately switch to the frequency points fH1 and fH3 of the train CIR equipment of two adjacent ground fixed stations A and C to collect field strength values. The frequency point fH1 of the ground fixed station A with the higher field strength value is selected for location update registration.

[0029] Regardless of whether the train CIR equipment is in the frequency point preparation reselection state, as long as the first scan shows that the field strength value of the fH1 frequency point of an adjacent station is 6dB higher than the field strength value of the fH2 frequency point of the current station, the fH3 frequency point of the second adjacent station will be scanned immediately, and the fH1 frequency point with the highest field strength value will be selected. The field strength value of the highest frequency point fH1 will be scanned 3 times, with an interval of 3 seconds between each scan; if two of the three scan results of the frequency point fH1 are higher than the field strength value of the current fH2 frequency point of the current station by 6db, the position update registration will be started with the adjacent station ground fixed station A; if two of the three scan results of the frequency point fH1 are lower than the field strength value of the current fH2 frequency point of the current station, it will immediately resume for 5 seconds and enter the frequency point preparation reselection state.

[0030] 2-4. Determine whether the field strength values ​​of the two adjacent ground fixed radio stations fH1 and fH3 frequency points are higher than the field strength value of the station's fH2 frequency point. If so, perform location update registration with the adjacent fixed radio station A at the fH1 frequency point with a higher field strength value; if not, return to step 2-1.

[0031] 2-5. The above principles for judging the field strength reselection mechanism of the train CIR equipment are implemented repeatedly during the operation along the way to ensure that the train CIR equipment and the ground fixed station with the highest field strength value perform real-time position update registration to realize the strong field reselection mechanism in the DRTD communication system and ensure the call quality between the train CIR equipment and the ground fixed station.

Claims

1. A method for implementing a strong field reselection mechanism based on DRTD locomotive station, characterized in that: in, The strong field reselection mechanism is implemented based on the railway DRTD communication system, the communication system includes train CIR equipment and ground fixed radio stations, and the implementation method of the strong field reselection mechanism is: determining the judgment principle of the train CIR equipment startup scanning mechanism and the train CIR equipment strong field reselection mechanism; 1. Train CIR equipment startup scanning mechanism When the train CIR device of the DRTD locomotive station is turned on or switched to the DRTD mode, the power-on scanning mechanism is first performed to scan all the frequency points in the frequency group in turn, and the field strength value of each frequency point is read once. After polling each frequency point, the frequency point with the high field strength value is locked. The train CIR device performs position update registration with the ground fixed station, and the ground fixed station after the update registration is defined as the local station; 2. Judgment Principles of the Strong Field Reselection Mechanism of Train CIR Equipment a. After the train CIR device successfully updates the location registration with the station, multiple field strength values ​​of the station are collected during the journey, and the average value of the multiple field strength values ​​is calculated, and the average value of the multiple field strength values ​​is used as the field strength value of the station; If the field strength value of the station is found to decrease during the acquisition process, the train CIR equipment will enter the frequency point preparation reselection state; b. Determine whether the field strength value of the station is lower than the preset field strength value. If it is lower, start fast switching and immediately switch to the frequency points of the train CIR equipment of two adjacent ground fixed stations to collect field strength values, and select the ground fixed station with the higher field strength value for location update registration; c. Determine whether the field strength values ​​of the two adjacent ground fixed stations are higher than the field strength value of the station. If so, perform location update registration with the adjacent ground fixed station with the higher field strength value; if not, return to step a. d. Repeat steps a, b, and c to ensure that the judgment principle of real-time location update registration between the train CIR equipment and the ground fixed station with the highest field strength value is implemented to realize the strong field reselection mechanism in the DRTD communication system; The determination principle of the train CIR equipment strong field reselection mechanism is: regardless of whether the train CIR equipment is in the frequency point preparation reselection state, as long as the first scan shows that there is an adjacent station frequency point higher than the current station frequency point, the second adjacent station frequency point is immediately scanned, and the frequency point with the highest field strength value is selected. The field strength value of the highest frequency point is scanned three times, and the time interval between each scan is 3 seconds; If two of the three scanning results are higher than the current frequency strength value of this station, the location update registration will be started with the neighboring ground fixed station; if two of the three scanning results are lower than the current frequency strength value of this station, the frequency preparation reselection state will be restored immediately.

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